Geoff Parling's move from Newcastle was a big step but he craved the harsher environment of Leicester. Photograph: Stu Forster/Getty Images

Same old Leicester. Here they are in their eighth successive Premiership final, an extraordinary feat of consistency and stamina. A fourth title in six years would be some achievement but stealthy reinvention is their real talent. The Tigers starting pack at Twickenham on Saturday will contain only three players who kicked off their last winning final against Saracens in 2010. Chop off the Hydra's head and the beast grows back stronger than ever.

The Tigers also labour like Hercules out on the practice field. It has always been Leicester's way – train hard, then train harder – and the environment breeds hungry competitors undeterred by grand final bunting. In the case of Geoff Parling, the England lock, a good club professional has been swiftly transformed into an improving Test player ravenous for silverware of any description.

The Stockton-born Parling, one of 18 players involved at Twickenham who will fly out with England to South Africa on Wednesday, reckons he would still be uncapped had he stayed at his much-loved former club Newcastle. "Definitely. I craved this sort of environment. Pretty old school, a bit harsher. You can just concentrate on your rugby and everything else is taken care of. The medical department, the conditioning department, your kit all gets washed for you. It's a big level up."

The Premiership is an unequal society, even before you start contemplating the vexed subject of automatic promotion and relegation. Get recruited by Leicester and, according to Parling, you will become a better player virtually overnight. "You can't tell me that's just the player, it's the environment in which he's in," said Richard Cockerill in 2010, reflecting on the 6ft 6in tall second-row's selection for England's tour squad within 12 months of arriving in the East Midlands.

So how does this physiological transformation occur? Even Parling was slightly wary, having heard all the stories of training ground punch-ups and "Leicester bosh". Within days he felt totally at home. "It's not as bad as people think. We do a bit more brawling and the environment's harsher but, as a team, you need to find what works for you. At Leicester our thing is that we work hard, we're a bit more old school. Quins have got their thing. They're a very confident team, they've just been over to Abu Dhabi. If that works for them, brilliant. It'd be too hot for me, I'm from up north."

Leicester, furthermore, are under pressure to perform every week, not just occasionally. "Training with quality players, playing in the Heineken Cup, coping with the pressure of being expected to perform every week… it's made a world of difference. I don't think you're going to go from being a bad player to a good player here but it's going to help you improve. I came because I wanted to become better and to try to win things. I was getting frustrated with fighting relegation every year. As a player you've got a very short career and you've almost got to be a little selfish. At the time Leicester felt like the Manchester United of English rugby. I thought: 'Not many people get this chance, I don't want to turn them down.'"

The 28-year-old Parling, with his bushy beard, pale blue eyes, protruding backside and penchant for a good sing-song, is the kind of down-to-earth character who makes the Tigers tick. The only two defeats he has been involved with in 2012 have been Leicester's ill-fated Heineken Cup trip to Ulster in January and England's narrow defeat to Wales, his first start for his country.

Stuart Lancaster has been quick to appreciate his ability to run a lineout and Parling's performance in the away win over France in March has cemented a starting Test place.

He would not be human if he did have one eye on South Africa, where mountainous lock forwards come as standard and smashing the England front five will be a high priority. At Leicester, though, anyone looking too far ahead risks the wrath of Cockerill, who has worked wonders along with Matt O'Connor since the World Cup in hoisting the Tigers from 11th place in the table.

Parling reckons people underrate Cockerill. "Everyone has this vision of Cockers just being a very angry man. Sometimes he is. But he's also a bit more astute than everyone gives him credit for. He does a lot of homework."

Many underestimate Parling, too. His father, Geoff Sr, a retired teacher, played most his career for Stockton fifths and, in six years at Newcastle, his son won nothing. It is a different story now. In the 2010 final it was Parling's late lineout steal which clinched the trophy for the Tigers. Twelve months later he had to sit and watch Saracens turn the tables, having missed almost the entire season following neck and knee surgery. "I was absolutely gutted for the lads. I'm not a watcher of rugby, I want to be involved. Some people never get the opportunity to play in finals. It's all about making the most of it."

That, in a nutshell, is what makes Leicester so dangerous. Other clubs may think they're hungry but it is a relative concept. It matters not to Parling that an England rival, George Robson, will be in direct opposition. "I don't think it gives you an extra edge. It's a final. If you haven't got the extra edge for a Premiership final anyway you're probably in the wrong game. If we play well, we think we're good enough to beat them. We've just got to make sure we do that."